Yes, you are wrong
.
Let's assume that the range for your data validation list is on a hidden sheet called "Lookup", in cells A1 to A22. What you do is create a dynamic range name -
Insert | Name | Define. Type in the name for the range, and set the "Refers to" formula as
=OFFSET(Lookup!$A$1,0,0,COUNTA(Lookup!$A:$A),1)
This range will now cover all the populated cells in your list. If you add or remove items from the list, the size of the range name adjusts accordingly. Your data validation lists should all have their "Source" set to this dynamic range name.